Field of the Invention
The present invention relates to a sheet-processing apparatus that folds a sheet(s) and an image-forming system that uses such a sheet-processing apparatus.
Description of Related Art
A post-processing apparatus has been widely utilized. The post-processing apparatus has performed a predetermined post-processing on a sheet(s) on which an image-forming apparatus has already formed an image. The post-processing apparatus is connected with the image-forming apparatus in line at a downstream side along a sheet-conveying direction of the image-forming apparatus. The post-processing apparatus performs, for example, a center-fold finishing on a sheet(s). The post-processing apparatus performing the center-fold finishing contains a pair of folding rollers and a folding blade that thrusts a sheet(s) to a position between the pair of folding rollers to perform the center-fold finishing on the sheet(s) on a crease thereof.
For example, Japanese Patent Application Publication No. 2008-156113 has disclosed a post-processing apparatus in which a driving speed of a folding-rollers-driving motor varies during various kinds of processing steps such as a step until the blade attaches a bundle of sheets, a step while the bundle of folded sheets is conveyed to an outlet and a step of ejecting the bundle of folded sheets. Further, Japanese Patent Application Publication No. 2007-76832 has disclosed a sheet-processing apparatus including CPU which selects processing speeds of a thrust blade and folding rollers based on obtained sheet information and sheet information stored on ROM and controls operations of the thrust blade and the folding rollers based on the selected processing speeds thereof.